On Mon, 19 Dec 2011, Dimitry Andric wrote:
Log:
Some people pointed out long is 32-bit on some arches, while time_t is
64-bit, so better cast time_t to intmax_t, and use the appropriate
printf format strings.
Some pointed out that long is adequate. It works on all arches until
2038. It works on all arches with 64-bit longs for a measly 292
billion years. timed deals with current times, so times after 2038
can't happen for it yet. So long only fails for arches still using
32-bit longs in 2038. It's not as if casting to intmax_t is correct
in all cases. time_t might be unsigned, or floating point.
Modified: head/usr.sbin/timed/timed/correct.c
==============================================================================
--- head/usr.sbin/timed/timed/correct.c Mon Dec 19 20:01:21 2011
(r228718)
+++ head/usr.sbin/timed/timed/correct.c Mon Dec 19 20:29:50 2011
(r228719)
@@ -162,8 +162,8 @@ adjclock(corr)
}
} else {
syslog(LOG_WARNING,
- "clock correction %ld sec too large to adjust",
- (long)adj.tv_sec);
+ "clock correction %jd sec too large to adjust",
+ (intmax_t)adj.tv_sec);
This is a for time delta, so it doesn't even run out with 32-bit
longs in 2038. It runs out when the time difference between systems
exceeds 68+ years. If you have such a difference, then you have more
problems than misprinting it by truncating it to long.
(void) gettimeofday(&now, 0);
timevaladd(&now, corr);
if (settimeofday(&now, 0) < 0)
Modified: head/usr.sbin/timed/timed/readmsg.c
==============================================================================
--- head/usr.sbin/timed/timed/readmsg.c Mon Dec 19 20:01:21 2011
(r228718)
+++ head/usr.sbin/timed/timed/readmsg.c Mon Dec 19 20:29:50 2011
(r228719)
@@ -181,8 +181,8 @@ again:
rwait.tv_usec = 1000000/CLK_TCK;
if (trace) {
- fprintf(fd, "readmsg: wait %ld.%6ld at %s\n",
- (long)rwait.tv_sec, rwait.tv_usec, date());
+ fprintf(fd, "readmsg: wait %jd.%6ld at %s\n",
+ (intmax_t)rwait.tv_sec, rwait.tv_usec, date());
This is also for a time difference. It will soon be passed to select()
as a timeout. If we are asking for a select timeout of 68+ years, then
we have worse problems than misprinting it in debugging code.
/* Notice a full disk, as we flush trace info.
* It is better to flush periodically than at
* every line because the tracing consists of bursts
Supporting time differences of 292 billion years is silly. If you do that,
then you should worry about time_t being 128-bit long double, while
intmax_t is a mere 64 bits. 128-bit long double can only go up to
3*10**17 billion years before losing precision. But when it does, you
should be more careful not to blindly truncate it to intmax_t.
Bruce
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